Improvement in cut-offs for steam-engines



UNIT-Ensures 'PATENT' OFFICE.

4DAivinL A. wooDBURY, oRocHEsTER, NEW YORK.

lmp'RovEMl-:NT IN Vcu-r-oFFs FpoR STEAM-ENGINES- Specification forming`part of `Letters Patent o. 154,363, dated August 25, 1874; applicationtiled i i February 20, 1874.

To all whom t may @encarar Be it known that I, DANIEL A. WOODBURY,

of Rochester, in the countyoil Monroe and State of New York, have`invented certain Improvements in .Automatic Cut-Offs for Steam-En#gines,of which the following is a specification: The object of myinvention is to provide a simple, durable, and ett'ective cut-oft gearwhich `f` can becontrolled with ease by thegovernor;

and lit. consists chieiiy in the useof .a balanced cylindrical cut-offvalve sliding in a chamber in the back of the mainvalve, and Aarrangedto admit steam? into passages in the latter by means of spiral portsinthe cut-ofi' valve-seat,

the point of 1cu't-oftfbeing determined by roll` ing'the valve in itsseat, and it further con- "ffsists in a method of compensating the4 wearof the valves and. seats. 1

In the drawing, Figure l is a'horizontal sectional view of my device.applied to the steamchest of a side engine. Fig'. 2 is a verticalsectional view of the cut-oft' valve and connections, showing thoseparts 'above the dotted line Fig. 1. Fig. 3 is a transverse section ofthe valves at the dotted line y, Fig. 1.

A, Figs. 1 and 3, is the main or distributing valve, moving upon a faceon the cylinder B in the usual manner, and having the ordinaryexhaust-passages, and also steam-passages c c,4 communicating withchambers formed in the back of the valve. Gis a cylindrical cut-0E valvetted closely into a seat provided in the main valve. This valve admitssteam from the chest D at its ends, and ports a a are provided in itsseat, which communicate, through the chambers before mentioned, with thesteamopenings c c in the face `of the main valve, as indicated by fulland dotted lines .in Figs. 1 and 3. The ports a a are cut spirallyaround the valve-seat, there being two or more openings near each endaround the periphery of the seat, as shown in Figs. 1 and3. Theextremities of the valve C are also of spiral form, to correspond withthe ports a a, and there are consequently two or more spiraladmissionedges, b, at each end, one foreach port a. The valve C isreciprocated in its seat by means of the stem d and the usual eccentricattachments, and it is plain that, if a rolling movement be imparted toit through the stem d, the point of cut-off will be varied, since thelength of .the valve is thus virtually altered.

It will be seen that by this construction of `valve and arrangement ofports the former is perfectlyV balanced, the steam pressing upon `itequally in all directions, whether the ports be open or closed, and thatthus the force necessary to work it is reduced to the minimum, and, atthe same time, it is perfectly free to be rotated by the governorthrough suitable couynections. The latter, particularly, isa greatdesideratum, since in the valves of this class heretofore used thepressure upon them, when a port was closed, was so great as to hinder,if

, not actually prevent, the action of the governor.

y The spindle d passes freely through the valve C to that extremityopposite the sturling-box e, and is rigidly fastened to it by aset-screw, j', Fig.' 1,v or other suitable device. By this .means theelasticity of. the rod is made available to allowthe valves to wear upontheir seats within certain limits, and also to permit the main valve toretreat in case of water gathering in the cylinder. By thusmaking thedistance between the stuffing-box and the point f considerable, theattachment of the valve to I the rod is much simplied, for it is foundnecessary to make some provision for change in position of the valves,and this plan allows the change to occur as necessity requires, withinsmall limits.` The valve-stem d is secured at its outer extremity to thesleeve or enlarged rod g, Figs. 1, 2, and 4, which is supported inbearings inthe bracket E. This bracket is Y.

bolted steam-tight to the face of thev steamchest D, and receives thestuffing-box e. The sleeve g has a ball-and-socket joint at itsextremity, which forms the attachment `to the eccentric-rod, and isprovided with longitudinal grooves, (shownin Fig. 4,) into which splinesin the arm t it. This arm is located between the two bearings m and n ofthe bracket E, and consequently has no lateral movement, but permitsthat of the sleeve g through it. The rod j is pivoted to the outer endof the arm t', and proceeds to au ordinary centrifugal governor or othersuitable regulating device. Thus it will be observed that the sleeve g,stem d, and valve are free to move longitudinally in vobedience to theeccentric, while, at the same amounts of adjustment. lThe upper face oftime, a circumferential movement may be im. parted to -them through thesplined arm, thus adjusting the point of cut-o'. The openingl in theWall of the steam-chest, through which the stem d passes, isconsiderably larger than such stem, and the bracket E is made adjustablealong the face ofthe steam-.chest by means of slotted bolt-holes orotherwise. By this means, when the Wear of the valve-seats becomesgreater than the elasticity ofthe rod d is able to compensate, thestuliing-box and supporting-bearings of the valve-stem may be adjustedto correspond with such Wear, and in the case of a side engine, with thesettling of the valve upon its supporting-surface also. This adjustmentof the bracket E is not a substitute forthe compensation obtained by theelasticity of the rod d, but is intended as an adjunct thereto, thatderived from the rod being automatic and Within small limits, While theother is available for larger and fixed the bracket E also affords aconvenient base for the support of the governing device, in case suchlocation is desirable.

The cnt-off valve may be a hollow cylinder, having suitable provisionfor attaching the stem d, and, instead of the admission-edges b, spiralopenings may be formed in its shell, the operation being the same ineithercas'e.

The ball-joint h permits the rolling movement of the rod g, and also thevertical swing of the eccentric-rod; and it Will be observed in this, asWell as in regard to the frictional surfaces of the sleeve g, rod d, andvalve C, there is a continuous positive movement imparted 4 vloy theeccentric, which greatly facilitates the other part of the valve C, andthe flexibility of the valve-stem still retained.

I am aware that slide-valves having a rolling adjustment in their seats,in connection with spiral vor diagonal ports and correspondingadmission-edges on the valves, are in u se, and I dol not claim suchconstruction of valve and arrangement of ports; but

What I claim as my invention is- 1. The cylindrical cut-off valve C,provided with ports or admission-edges b, and capable of a rollingadjustment in its seat in the main valve, in combination with the mainvalve A, having spiral ports a and passages c, substantially as and forthe purpose set forth.

2. In combination With a valve, C, having a rolling movement in itsseat, the stuffing-box e, made adjustable along the face of thesteamchest laterally to the valve-spindle, for the purpose of followingup the Wear ofthe valve and seat.

3. In combination with a valve, G, having a rolling movement in itsseat, the bracket E, supporting the stufing-box e and spindle-bear-Aings m and n, and 'capable of adj ustmentV along the face of thesteam-chest, substantially as'- and for the purpose set forth. lWitnesses: D. A. WOODBURY.

JAMES E. BOOTH, WM. A. MONTGOMERY.

